Plunger lift device



Jl me 16,- 1953 Nox ETAL 2,642,002

, PLUNGER LIFT DEVICE Filed March 28, 1949 3 Sheets-Sheet 1illlllllillllllmmm mmvroxs DOA/9L0 KNOX kn ves mweE//c'E,./e. v

June 16, 1953 I D. e. KNOX ETALI.

PLUNGER LIFT DEVICE s Sheets-Sheet 2 Filed March 28, 1949 June 16, 19532 ammo a. m/ax aqua-s :0. mums-wee .xe.

INVENT6RS.

provide a plunger body Patented June 16, 1953 PLUNGER LIFT DEVICE DonaldG. Knox, Long Beach, and James W. Lawrence, Jr., Los Angeles, Calif.,assignors to The'National Supply Company, Pittsburgh, Pa... acorporation of Pennsylvania Application March 28, 1949, Serial No.83,850

This invention relates to plunger lift apparatus for raising fluid froma well by means of fluid pressure acting on a plunger which travels thefull length of the eduction tubing. This invention is particularlydirected to'improvements in the construction of the plunger.

One of the difliculties encountered in the operation of plunger liftdevices has been the slip"- page and consequent loss of well fluidbetween the eduction tubing and the fluid operated plunger. It has beennecessary to make the plunger considerably undersized in order that itmay travel freely within the tubing, because the tubing is not machinedon its inside surface. It is not practicable to employ piston ring typeseals for minimizing slippage of well fluid between the plunger and theeduction tubing because such seal rings will not freely pass the jointsconnect ing the individual lengths of eduction tubing.

It is the principal object of this invention to provide a plungeremploying a set of compensating shoes which perform the function of anexpansion type piston ring and yet which is constructed to pass acrossrecesses at each coupling jointwithout jamming and without detrimentaleffects.

A more detailed object of this invention is to having expansible ringsegments acting to seal against the inside surface of the eductiontubing, which segments is regulated by radially movable membersextending axially of the plunger body.

Other and more detailed objects and advantages will appear hereinafter.x

In the drawings: Figure l is a diagrammatic sectional view of a plungerlift installation and showing a plunger the radial position of;

' 8 Claims. (01. 103-52) embodying this invention positioned within aneduction tubing.

Figure 2 is a sectional elevation of the upper of Figure 2. I

Figure 4 is a transverse sectional view taken substantially on the lines5-4 as shown in Figure 2.

Figure 5 is a perspective view partly broken away showing the assemblyof the depression bars and ring segments, the plunger body being omitted-for clarity of illustration.

- vFigure 6 is a perspective view of the plunger assembly.

Figure '7 is a sectional view taken substantially on the line 1-4 asshown in Figure 6.

Referring to the drawings, the swab plunger assembly generallydesignated it is positioned Within a sectional eduction tubing H whichex-- tends into a well bore 12. The bore may be provided with the usualcasing i3. Gas under pressure admitted through'valve l4 passesdownwardly in the annulus I5 between the casing and eduction tubing andacts to cause the well fluid to pass upwardly into the footpieceassembly is at the bottom of the well. The well fluid rises in the lowerend of the eduction tubing H. The plunger assembly it drops by gravitythrough the interior of the eduction tubing until it strikes the bumperI! which is supported on the spring l8. A valve in the plunger assemblycloses and gas pressure below the plunger assembly i0 then causes it tomove upwardly through the eduction tubing, raising a load of well fluidabove it. The well fluid is discharged through ports [9 in the flownipple 22 and passes outwardly through a restriction valve 2!, Thereduction in pressure beneath the plunger assembly Ill then allows itsvalve to open by gravity and the plunger descends by gravity to start anew cycle.

Since the eduction tubing ll may be several thousand feet in length itis composed of individual tubing sections 22 connected by couplingcollars 23. The adjacent ends of tubing sections do not necessarily meetin abutting contact, but

and which avoid fouling or interference when the plunger assembly passesover a joint between adjacent tubing sections 22.

.As shown in the drawings, the plunger assembly I0 includes a body 26having an end'piece 21 secured at its upper end by means of threads 28and a valve cage 29 secured at its lower end by means of threads 30. Apair of expandible sealing assemblies is provided on the body, and eachof these assemblies includes a plurality of ring segments 3| which arereceived in a circumferential groove 32 provided on the body 26. Thisgroove intersects a plurality of longitudinal slots 33 which extendaxially of the body and receive axially extending deflector bars 34,.The ring segments 3| are notched adjacent their ends as shown at 35 andthe bars 34 are each provided with a central relief 36 and side notches31 which interfit with the notched ends of the ring segments 3|. Thisarrangement is clearly shown in Figure 5. The depths of the notches 35and of the reliefs 36 are such that when the segments 3| and bars 34 arein fully extended position, as shown in Figure 4, a continuous circle isformed by the outer surfaces of the bars and segments.

Each of the ring segments 3| is provided with a radially extendingrecess 38 for reception of a compression spring 39. The inner ends ofeach of the compression springs 39 rest in the circumferential groove32. The action of these springs is to urge the segments 3| to moveradially outwardly. The bars 3 2 each overlie a joint between adjacentring sections 3| and serve to limit outward movement of the segmentsunder influence of the compression springs 33. Each of the bars 35 isprovided with axially ex tending lips it at its opposed ends, and theselips 40 extend within counterbores ill provided at the ends of the valvecage 29 and end piece 21. The bars 3 are free to move radially withinthe longitudinal slots 33 and to tilt within the slots, but the extentof such movement is limited by engagement of the lips it within thecounterbores 4|. It will be observed that each of the bars 34 is bowedon its outer surface so that the contour is straight for a portion ofthe bar length and then tapers off on both ends toward the plungerdiameter so that when the bars are fully depressed into the slots 33,the maximum projection of the bars beyond the outside diameter of theend piece 2? and valve cage 29 is reduced to a minimum. When the barsare fully extended as shown in Figures 2 and 3,

their outer surfaces adjacent the extreme ends lie flush with theoutside diameter of the end piece 2'! and valve cage 29.

The cage 29 is provided with a tapered seat and described in thecopending application of 1* Donald G. Knox, Serial No. 767,401, filedAugust 8, 1947, may be mounted within the cage 29 and held in placeagainst a shoulder 41 by means of bushing 45 and resilient washer 43.The function of this magnet is to assist in maintaining the valve '43 inopen position as shown by the dotted lines in Figure 3. The valve ismaintained in closed position by gas pressure within the eduction tubingbelow the plunger assembly II. A choke ring 43 which is of slightlysmaller outside diameter than the end piece 27 and valve cage 29 may bemounted on the lower end 'of the bushing 45 and held in place by meansof a suitable snap ring 50.

When two expansible sealing assemblies are used as shown in thedrawings, it is desirable that the slots 33 in the upper assembly bepositioned out of line with the slots in the other assembly. In theparticular construction shown, using four depression bars 34 in each ofthe assemblies, it is preferable to position the slots 33 in oneassembly at an angle of 45 with respect to the slots in the otherassembly.

In operation the swab plunger I travels ver-,

'tically within the eduction tubing 11, and the 4, expansible sealingassemblies form a substantially fluid-tight fit within the interior ofthe I segments 3| radially inwardly to prevent inter- 'ference.

The springs 39 are sufliciently strong to maintain the ring segments anddepression bars in sealing relationship with the eduction tubing, butpermit contraction of the sealing assemblies in tight spots in thetubing without creating undue friction. The possibility of hanging up atjoints between adjacent tubing sections is eliminated.

Actual field use has demonstrated that the slippage of well fluidbetween the plunger l0 and tubing H is materially reduced when theplunger incorporates the present invention.

Having fully described out invention, it is to be understood that we donot Wish to be limited to the details herein set forth, but ourinvention is of the full scope of the appended claims.

We claim:

1. A fluid operated swab plunger for travel in a sectional eductiontubing, comprising in combination: a body member, cooperating valveparts on the body member operable to prevent flow of fluid therethrough,a plurality of longitudinal deflector bars circumferentially spacedaround the body member and mounted for radial movement relative to thebody member, a segmental ring mountedfor radial movement on the bodymember and positioned between the ends of the deflector bars, resilientmeans on the body memher acting to move the ring segments and1ongitudinal bars outwardly for sealing contact with the interior of theeduction tubing, the outer surface of each of the deflector bars beincurvedto cooperate with the ring segments to form substantially fullcircle contact with the interior of the eduction tubing.

2. A fluid operated swab plunger for travel in a sectional eductiontubing, comprising in combination: a tubular body member, a valve on thebody member operable to prevent flow of fluid therethrough, a pluralityof ring segments mounted for radial movement on the body member,resilient means on the body member acting to move the ring segmentsoutwardly for sealing contact with the interior of the eduction tubing,a plurality of longitudinal deflector bars circumferentially spacedaround the body member and mounted for radial movement relative to thebody member, the outer surface of each of the deflector bars beingshaped for contact with the interior of the eduction tubing, thedeflector bars each overlying opposed ends of adjacent ring segments,and means on the body member for limiting outward movement of the bars.

3. A fluid operated swab plunger adapted for travel in a sectionaleducation tubing, comprising in combination: a tubular body memberprovided with axially extending slots and a circumferential grooveintersecting the slots, ring segments mounted for radial movement in thegroove, resilient means on the body member acting to move the ringsegments outwardly for contact with the interior of the eduction tubwithtwo sets of axially extending slots, the

slots in the first set being circumferentially staggered with respect tothe second set, the body member having two circumferential grooves, oneintersecting each set of slots, ring segments mounted for radialmovement in each groove, resilient means on the body member acting tomove the ring segments outwardly for contact with the interior of theeduction tubing, a plurality of axially extending deflector barsreceived in the body member slots and adapted to limit outward movementof the ring segments, the outer surface of each of the deflector barsbein shaped for contact with the interior of the eduction tubing,cooperating valve parts on the body member operable to prevent flow offluid therethrough, and means on the body member for limiting outwardmovement of the bars.

5. A fluid operated swab plunger for travel in a sectional eductiontubing, comprising in combination: an elongated body member, cooperatingvalve parts on the body member operable to preventflow of fluidtherethrough, a plurality of axially extending deflector barscircumferentially spaced on the body and each mounted for radialmovement relative to the body, the outer surface of each of thedeflector bars being transversely curved and being coni vexly bowed inan axial direction, circumferentially extending ring segment elementsoperatively associated with the bars intermediate the ends thereof andhaving outer'surfaces forming circumferential continuations of theadjacent portions of the outer surfaces of the bars, and cooperatingtherewith to form substantially full circle contact with the interior ofthe eduction tubing.

6. A fluid operated swab plunger for travel in a sectional eductiontubing, comprising in combination: an elongated body member, cooperatingvalve parts on the body member operable to prevent flow of fluidtherethrough, a plurality of axially extending deflector barscircumferentially spaced on the body and each mounted for radialmovement relative to the body, the outer surface of each of thedeflector bars being transversely curved and being convexly bowed in anaxial direction, circumferentially extending ring segment elementsoperatively associated with the bars intermediate the ends thereof andhaving outer surfaces forming circumferential continuations of theadjacent portions of the outer surfaces of the bars, and cooperatingtherewith to form substantially full circle contact with the interior ofthe eduction tubing, and resilient means on the body member acting tomove the bars and ring se ments radially outwardly.

7. A fluid operated swab plunger for travel in a sectional eductiontubing, comprising in combination: a tubular body member provided with aplurality of axially extending circumferentially spaced slots,cooperating valve parts on the body member operable to prevent flow offluid therethrough, a plurality ofaxially extending deflector bars eachmounted for radial movement in one of said slots, the outer surface ofeach of the deflector bars being transversely curved and being convexlybowed in an axial direction, circumferentially extending ring se mentelements operatively associated with the bars intermediate the endsthereof and havin outer surfaces forming circumferential continuationsof the adjacent portions of the outer surfaces of the bars, andcooperating therewith to form substantially full circle contact with theinterior of theeduction tubing.

8. A fluid operated swab plunger in a sectional eduction tubing,comprising in combination: a tubular body member provided with aplurality of axially extending circumfer entially spaced slots and acircumferential groove intersectingthe slots, cooperating valve parts onthe body member operable to prevent flow of fluid therethrough, aplurality of axially extending deflector bars each mounted for radialmovement in one of said slots, the outer surface of each of thedeflector bars being transversely curved and being convexly bowed in anaxial direction, circumferentially extending ring segment elementsoperatively associated with the bars intermediate the ends thereof andreceived in said groove, the said elements having outer surfaces formingcircumferential continuations of the adjacent portions of the outersurfaces of the bars, and cooperating therewith to form substantiallyfull circle contact with the interior of the eduction tubing.

DONALD G. KNOX.

Bell Apr. 27, 1943 for travel

